Plants which thrive in less-than-perfect conditions

Midwest Groundcovers' sustainable landscape by the international designer Piet Oudolf on Route 25 in St. Charles is open to the public during business hours.Courtesy midwestgroundcovers.com

Grace Koehler has favorite plants, and favorite combinations of plants. The problem is she has a lot of favorites, so we narrowed down the list she presented at the recent Mid-Am Horticultural Trade Show.

Koehler works for Midwest Groundcovers in St. Charles, a wholesale nursery, and carries green credentials as past president of the Midwest Ecological Landscaping Association.

This means most of the plants she recommends are tough, thrive in poor soil, require little water and often do not inspire desire in deer.

One caveat: When she says poor soil she does not mean solid clay - if you don't have fair drainage, Koehler recommends amending your garden.

Allium

It's hard to believe onions can produce such beautiful flowers. Koehler's favorite is Summer Beauty, not just for the pink blooms, but for the foliage, which she says makes these allium good to plant with or instead of day lilies, which are know for leaves that "look like heck."

"The foliage is green from the get go until the end in December. It's clean, tidy, bright green and doesn't change," she said.

Butterflies love Summer Beauty, which grows about 24 inches tall, and she pairs it in gardens or containers with calamintha nepeta nepeta, which attracts honey bees and pollinators.

The calamintha will not reseed and blooms with light blue summer flowers. After frost the flowers are pinkish white until Thanksgiving. Calamintha, which grows 12 to 15 inches tall, even works in a formal setting with sheared boxwood.

Another choice to pair with allium is origanum Herrenhausen or ornamental oregano, and Koehler likes the 16-inch plants with striking purple flowers weaving through the allium.

She has seen the oregano grow in gravel, and there are hints it could become invasive in good soils with moisture.

If you're looking for a grass to share with your allium, sesleria autumnalis grows 18 inches with a tight habit and produces seed heads in August.

Combination that tolerates salt and some shade

Amsonia Blue Ice grows taller, 24 to 36 inches, with soft blue flowers in early spring. The foliage is darker and lasts through the season.

Anemone Silvestris with its white flowers is about 16 inches tall and can grow along a sidewalk. Veronica Waterperry Blue is only 4-6 inches tall and is long flowering with softer flowers than the taller veronicas.

Echinacea

It's always good to have advice for wending our way through the huge variety of new coneflowers. Koehler says give echinacea organic material but not fertilizer, and she usually pulls any that revert to the species.

Oh, if rabbits are a problem, her advice is to get a fox.

The Pink Tennessee at 20 to 30 inches tall is Koehler's favorite. These are known for following the sun like sunflowers, and for putting up with drier soils once established.

Coconut Lime, a double with green pompon and white petals, seems to bloom longer than any of the other greens. The Pink Double Delight is another pompon.

•Blue Heaven little bluestem is a grass that does not flop, and in midsummer the foliage turns to burgundy.

•Panicum virgatum is for gardeners looking for a grass that grows 6-8 feet with good fall color and no disease susceptibilities.

•Salvia Purple Rain. If you want a midsummer show, this is a different look than some salvia because it has coarser texture but is nice and upright. She likes it in containers.

•You want your monarda to be mildew-resistant. Grand Marshall is a little taller than Grand Parade, which grows 16 to 20 inches. For a different color, try Coral Reef, which is in the 24-36-inch range.

•Jolly Bee geranium or cranesbill sometimes blooms through December, and the foliage turns red in the fall. It is vigorous but not invasive. Karmina provides bright orange fall color as a ground cover, and Hocus Pocus wears deep-cut leaves.

•Minnie Pearl phlox blooms in May, does not mold and grows 12 to 15 inches.

•Salvia Marcus is a short ground cover that only reaches 12 inches. If you're looking for a perennial with big, tropical-like leaves, Koehler recommends ligularia Britt-Marie Crawford. Friends will be impressed with the dark-chocolate, purple leaves and the late-summer golden daisylike flowers.